Compression or depression pump of the liquid ring type



March 14, 1944. R. l., DARDELET 2,344,396

COMPRESSION OR DEPRESSION PUMP OF THE LIQUID RING TYPE A Filed Jan. 9, 1941 Patented Mar. 14, 1944 COMPRESSION OR DEPRESSION PUMP OF THE LIQUID RING TYPE Robert Lon Dardelet, Grenoble, France; vested in the Alien Property Custodian Application January 9, 1941, Serial No. 373,839 In France January 22, 1940 Claims.

The present invention relates to rotary depression and compression pumps for gases (vacuum pumps and compressors) of the liquid ring type, including a hollow body containing a quantity liquid, at least one rotor within the body having displacement recesses and rotating with the least possible clearance in contact with one or more stationary circular surfaces called distributors provided with suction and delivery openings, formed by one or more ports, for the passage of the gases which are respectively sucked from and delivered into the compartments or recesses formed between the blades by the rotating liquid ring formed under the action of centrifugal force and following the internal contour of said body which is formed with at least one lobe.

It has been found that in such pumps, a given angular position of the inlet of the delivery opening or openings in the direction of rotation of the rotor is only suitable for a definite rate of operation, that is to say for a definite delivery pressure or for a definite vacuum. When a pump whose distributor is suitable fora certain rate of operation, operates at a diierent rate, the cornmunication betweenthe delivery openings and the recesses of the rotor is effected too soon or too late. This produces overpressures that increase the power absorbed by the pump and disturb the operation. Y

An object of this invention is to provide a gas pump of the liquid ring type which may be used for a whole scale of rates of operation while keeping the efliciency at its highest value and without any adjustments being required.

A further object of this invention is to provide` a gas pump of the liquid `ring type in which the angular position of the inlet of the delivery passage or passages opens to the gases carried along by the rotor and automatically varies itself according to the rate of operation towhich it automatically adapts itself. o. Y

A still further object of this invention is to provide `in a pump of the above character, a delivery passage in which the inlet part of which is provided with a valve arrangement mounted to allow only the gases coming from the recesses of the rotor to pass when their pressure exceeds the delivery pressure of the gases.

According to an embodiment of this invention, the delivery opening or openings of the distributor are formed by a number lof elongated elementary ports spaced in the direction of the rotation of the rotor, and with at least one port of which there co-operates a rod-shaped valve which is kept in register with the opening by a guiding device and which is directly exposed to the delivery pressure of the pump.

These longitudinal ports are continuous or are formed by a row of holes or the like.

According to anotherembodiment of this invention, the delivery opening or openings of thel distributor are at least partly closed by at least one valve, which is elongated in the direction of the rotation and is made of flexible material, in such a manner as to uncover a more or less great length of the opening with which it co-operates, according to the pressure to which it is subjected.

The said valve may be free, but is preferably fixed at one of its ends on the distributor and co-operates with abutments that limit its movement.

The delivery opening or openings may in this case be continuous or be formed by elementary ports which are preferably spaced in the direction of the rotation of the rotor. Each of said openings may, moreover, comprise a plurality of ports, each of which is conjugated with its own valve.

Other features, objects and advantages of this invention will moreover become apparent from the ensuing description made with reference to the accompanying drawing which is given solely by way of example and in which:

Fig. 1 is a sectional elevation of a liquid ring air pump; l

Fig. 2 is a partial similar view, on a large scale, showing the arrangement according to the invention;

Figi 3 is a section along the line III- III of Fig. 2.

Fig, 4 is a similar view to Fig. 2 and relates to a modification.

Fig. 5 is a-section along the line V--V of Fig. 4;

Fig. 6 is a similar view to Figs. 2 and 4, and relates to another modication.

FFigi. 7 is a section along the line VII-VII of 1g.

Figs. 8 and 9 are detail views of modifications of Fig. 7.

In order to facilitate the explanation and in a nowise limitative manner, all these figures relate more particularly to a pump with a single rotor and with an internal distributor and with two lobes formed in the pump body. The said pump comprises, referring to Fig. 1, an elongated body I including a pump chamber having enlarged portions or lobes.` at opposite sides, the major axis of said chamber being vertical. 'I'he rotor 2 is provided with blades 3. In the median part of the rotor 2 are tted one or a plurality through the openings B and 8 ofany desired gas.

According to the embodiment shown in Figs. 2 and 3, the delivery opening 8 is formed by a number of elementary longitudinal ports 8a, Bb,

8c, 8d, 8e, 8f. Said ports are elongated in the l axial direction and are spaced from each other in the direction of the arrow f. They are shown as being continuous, but could, of course, be formed by a plurality of holes or openings.

Each of the ports, save the last one 8f in the direction of the arrow f, co-operates with a valve formed Iby a rod Ia, Iib, I8c, Idd, Ille, of cylindrical or other shape, the diameter of which is greater than the width of the co-operating port. The said rods are arranged on the inner side of the distributor. The said rods may be of any suitable cross-section and are made of flexible material such as rubber, or again they may be rigid, for example made of steel, cuprous metal, glass, stoneware or other material.

Guides I2, I3 and I4 respectively embrace said rods at their ends and at their central part with a clearance that enables them to move between their operative position in which they close the co-operating ports and a position that uncovers said ports.

It will be understood that the retaining valves thus formed remain closed as long as the pressure in the distributor is higher. than the presM sure in the recesses formed between the blades, with which recesses said valves 'are in Contact. This latter pressure increases in the direction of the arrow f owing to the action of the liquid ring I8 so that the valve 8d which is opposite a lrecess of the rotor in which the pressure reaches this delivery pressure, is openedas well as those following itin the direction of the arrow ;f. The position ofthe first opened valvevaries according to the rate of operation of the air pump, and no substantial overpressure can occur.

According to the embodiment shown in Figs. li and 5, the valves I8 are replaced by a single deformable valve I5 which is elongated in the direction of rotation f of the rotor and is capable of covering the ports 8a to Se inclusive. The valve i5, which is formed by a strip of rubber or of fiexible metal, is xed by a screw I'I on a fixing member I8 before the ports 8 inthe direction of the arrow f, and its opening travel is limited by abutments i9 iixed inside the distributor.

It will be understood that said valve i5 is deformed, shown in dotted lines, and uncovers the ports 8 more or less according to the rate of the operation of the pump, as'explained in connection with the above example. l

' Referring to Figs. 6 and '7, the delivery port or ports, such as A2l), are elongated in the direction of rotation f so as to permit the maximum opening of the gas passage. Said port 20, the crosssectional width of which decreases as it is more remote from the' axis, co-operates in this case with a deformable valve I5 of thesame shape for which it acts as a housing and which is held at its upperend in the direction of the arrow f by a screw I1 on a transverse stop member I8 xed to the distributor.

Abutments I8 limit the opening travel of this valve I5 which is effected over a more or less great length according to the rate of operation of the pump.

Absolute progressiveness of the uncovering of the discharge opening in the direction opposite to the arrow f is thus obtained.

The cross-section of the opening 20 may be provided with a shoulder as shown in Fig. 8, the valve I5 being in this case of corresponding shape.

The valve I5 may be made of flexible material and be reinforced with transverse metal bars 2|, as shown in Fig. 9.

While I have specically described forms that myv invention may assume in practice, it will be understood that these forms have only been given by way of example and it is obvious that my invention is applicable to any construction of liquid ring compression or depression pump for gases, Iwhatever be the shape of the distributors and the number of rotors, without departing from its spirit or the scope of the appended claims.

What I claim is:

l. In a compression or depression pump of the liquid ring type `comprising astator, ay rotor therein having displacement recesses and at least one circular surface coaxial with said rotor and having at least one inlet opening and vone-discharge opening extending therethrough, the displacement recesses in the rotor co-operating with said circular surface and with liquid contained in the stator to create a pressure dierence between the said openings, said discharge opening including a member of elongated ports spaced apart in the direction of the rotation of the rotor', movable rod-shaped elements in register with at least a part of said ports, and arranged onvthe other side of said circular surface with respect to the'rotor, guiding means mounting each of said elements for free displacement between a working position in which saidelement obturates .the corresponding port, and a further position uncovering said port, whereby the said elements are directly exposed to the delivery pressure of the pump and the gases coming from the displacement recesses in the rotor and are only allowed to pass when their pressure exceeds the said delivery pressure.

2. A compression or depression pump as claimed in claim 1, in which' the said ports are substantially at rightV angle with reference to the direc'- tion of rotation of the rotor.

3. A compression or depression pump as claimed in claim l, in which the "said circular surface is substantially formed'by ahub on which the rotor is journalled, and within which are Amounted the said elongated elements. f

4. A compressionror depression pump ofthe liquid ring type comprising a statona rotorl having displacement recesses -andat least onelcircular surface coaxial with said rotor and having atleast one -inlet opening and oneV discharge opening Y extending therethrough, the displacement recesses in the rotor co-operating with said circular surface, said discharge openingincluding a number of slots substantially at-right angle with reference to the direction of rotation of the rotor and spaced apart in the said direction, movable rod-shaped elements on theV other side of saidsurface with referenceto the rotor, guid-4 ing means carried by said surface andembracing said rods with clearance and arranged toallow each of said rods to close a corresponding slot, whereby the said elements are directly exposed to the delivery pressure of the pump and the gases coming from the displacement recesses in the rotor are only allowed to pass through said slots When their pressure exceeds the said delivery pressure.

5. A compression or depression pump as claimed in claim 4, in which the elongated rods are only provided in register with at least the first slots of said opening in the direction olf rotation of the rotor.

6. In a compression or depression pump of the liquid ring type comprising a stator, a rotor therein having displacement recesses and at least one xed circular surface coaxial with said rotor and having at least one inlet opening and one discharge opening extending therethrough, a plurality'of displacement recesses in the rotor co-operating with said circular surface and with the liquid contained in the stator, said discharge opening including at least one slot elongated in a direction substantially parallel to the direction of rotation of the rotor and encompassing a plurality of the displacement recesses, at least one flexible Valve member elongated in the same direction and operative to obturate at least a part of the inlet of said discharge slot, said slot acting as a housing for the valve member when said member is seated, and said valve member being mounted for deformation on the other side of said surface with recference to the rotor, one end of said member being fixed in said slot at one end of the slot on its longitudinal axis, and the other end of the member being free and spaced from the opposite end of the slot, thereby more or less uncovering the discharge opening under the action of the pressure of the gases.

7. A compression or depression pump of the liquid ring type as claimed in claim 6, including abutments spaced in the direction of rotation of the rotor and in register with said valve member and adapted to limit its opening travel.

8. A compression or depression pump of the liquid ring type as claimed in claim 6 including means for fixing said valve member to said surface becfore the said discharge opening in the direction of rotation of the rotor.

9. In a compression or depression pump of the liquid ring type comprising a stator, a rotor therein having displacement recesses and at least one I'lxed port member having at least one inlet and one outlet opening extending therethrough, the displacement recesses in the rotor co-operating with said circular surface and with the liquid contained in the stator to create a pressure diierence between the inlet and the outlet openings, the discharge opening comprising at least one slot elongated in the direction of rotation of the rotor, a valve member elongated in the same direction and adapted to obturate at least the originof the said slot in the said direction, this valve member including a flexible and deformable blade housed in the said slot and so arranged that its external surface is at rest substantially united with the outer surface of the port member and means for fixing on the port member the origin of the blade in the said direction.

10. A compression or depression pump as claimed in claim 9, including further transversal rigid bars embedded in the blade.

ROBERT LE'oN DARDELET.

CERTIFICATE OE CORRECTION. Patent No. 2,5LTLLJ96. March 11T, 19m.

ROBERT LEON DARDETET.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second Column, line 56, claim l, for "member" read -number and that the .Said

Letters Patent should be read with this correction therein that the same may Conform to the record of the case in the Patent Office.

signed and sealed this 9th day of may, A. D. 19m.

^ Leslie Frazer (Seal) v Acting Commissioner of Patents. 

